A position estimation apparatus (10) acquires target information (31) regarding the position of a target body (100) and acquires neighboring information (32) regarding the position of a neighboring body, which is a movable body different from the target body (100), from the neighboring body. The position estimation apparatus (10) determines, as a primary area (41), a relative area in which the neighboring body is estimated to be present from the target information (31) and the neighboring information (32). The position estimation apparatus (10) calculates a probability of presence (43) of the neighboring body in each relative area from a plurality of the primary areas (41) determined within a reference period and determines, as a secondary area (44), a relative area in which the neighboring body is estimated to be present on the basis of the probability of presence (43).